No eyemasks or earplugs, uncofortable
No drugs, uncomfortable
Alcohol, ok maybe a couple.

If in economy, I bring one or two extra pillows, and take the window, preferable exit row, to avoid being bumped in the tight aisles.

Luckily I can fall asleep anywhere if tired enough. economy, biz, first, doesnt matter, done it all, slept well. Sometimes I feel biz class flights are wasted on me, because I can just sleep in economy just fine. Maybe that will change once I hit old age in a few decades.

I try to take the late departures to Europe, arriving as late as possible in the morning. Like 5pm departure, 6am arrival - no good, your body will think its just midnight. 11pm departure and noon arrival, great, your body thinks its 6am.. Asia, I try to take the midnight departure flights.